From what you say, it sounds like you were treated unfairly. Even if you had a side business, if it doesn't interfere with your job (take a look at the numbers, folks, they don't lie), then you should be able to sue successfully. All you have to do is produce the numbers to show your production and referrals were at least the same as, if not more than, the other guys. If you can do that, you could sue for wrongful termination, etc. Go to a lawyer who will do it pro bono unless you win (forgot the correct verbiage) and you have a suit that could take a year or more, BUT, you may win and win big. I doubt that you would have been let go in CA judging by your description of what happened. it sounds like a losing proposition for the company to let you go based on that if what you are saying is accurate.
Davy